CONDOR clinical trial: Brolucizumab superior to panretinal photocoagulation for proliferative diabetic retinopathy

The CONDOR randomized clinical trial (NCT04278417) showed both that brolucizumab (Beovu, Novartis) was superior to panretinal laser photocoagulation (PRP) for preserving visual acuity (VA) and that the drug may be a viable alternative therapy for treating patients with proliferative diabetic retinopathy (PDR).¹ The international team of investigators reported their results in JAMA Ophthalmology. First author Sebastian Wolf, MD, PhD, is from the Bern Photographic Reading Center, Department of Ophthalmology, University Hospital, University of Bern, Bern, Switzerland.

PRP has been the long-standing treatment for PDR and severe nonproliferative DR.² While the laser treatment efficacy is well-known, it is associated with potential complications, ie, choroidal effusions, exudative retinal detachments, macular edema, visual field deficits, and night vision defects,^3,4 according to the investigators.

Wolf and colleagues explained the rationale for their study. “Brolucizumab is a single-chain antibody fragment that has a high affinity for vascular endothelial growth factor (VEGF). A notable feature of brolucizumab is its low molecular weight (26 kDa), thus allowing a greater volume of drug per injection to be delivered to the retina compared with many other available anti-VEGF therapies. Preclinical data have shown that brolucizumab penetrates the retina to the level of the retinal pigment epithelium or choroid with minimal subsequent systemic exposure,^5” they said.

CONDOR methodology

The researchers from 152 sites in 16 countries in Europe, Asia, and North America are conducting a 96-week, phase 3, randomized clinical trial to investigate the efficacy and safety of brolucizumab, 6 mg, in eyes with PDR and compare the results with those of PRP.

Patients were included who had been diagnosed with diabetes and PDR and had undergone no previous PRP in the study eye. Those randomized to brolucizumab, 6 mg, underwent 3 loading doses every 6 weeks, followed by every 12 weeks, with the option from week 48 onward to extend the treatment interval by 6 weeks at a time up to 24 weeks based on disease activity, the authors recounted. Patients who were randomized to PRP received treatment in 1 to 4 sessions up to week 12, followed by additional as-needed PRP treatment.

The primary outcome was the change from baseline in the best-corrected VA (BCVA) at week 54. The secondary outcomes were the change in the progression of DR, the prevention of center-involved diabetic macular edema, the change in the diabetic retinopathy severity score levels, and safety.

What did the phase 3 CONDOR results show?

The study included 689 participants who were randomized to brolucizumab, 6 mg (n = 347), or PRP (n = 342); 572 randomized participants completed the week-54 evaluation.

The mean baseline BCVA letter score was 77.1 (20/32 Snellen equivalent).

Dr. Wolf and colleagues reported, “Brolucizumab, 6 mg, was noninferior and superior to PRP for the change in the BCVA at week 54, with a least-squares mean [standard error] change in letter score of 0.2 [0.72] vs −4.2 [0.73]; difference, 4.4; 95% confidence interval [CI], 2.4-6.4; P < 0.001).”

The results showed that more patients treated with brolucizumab had no PDR at the 54-week time point compared with the patients treated with PRP, 63.6% and 22.4%, respectively, which was a difference of 39.4% (P < 0.001).

More patients randomized to PRP experienced ocular adverse events compared with those randomized to brolucizumab, 49.1% vs. 34.3%, respectively.

Intraocular inflammation, including retinal vasculitis, developed in 5.2% of patients treated with brolucizumab compared with 0.6% treated with PRP.

The investigators concluded, “The findings from the current week-54 analysis of the CONDOR randomized clinical trial demonstrated superior outcomes with brolucizumab vs PRP in terms of preserving vision. Results from the future 96-week analysis will provide further insight into the longer-term efficacy of brolucizumab and its potential to improve visual outcomes with a manageable treatment burden in patients with PDR.”

According to Dr. Wolf and colleagues, their findings suggested that brolucizumab may control PDR by reversing disease progression and maintaining functional vision through the prevention of vision-threatening complications. Brolucizumab may be a viable treatment alternative to PRP for patients with PDR.

They also pointed out that the rate of intraocular inflammation was in line with the established safety profile of brolucizumab and no new safety signals were detected.

References

1. Wolf S, Chen Y, Li X, et al. Brolucizumab in the treatment of proliferative diabetic retinopathy: the CONDOR randomized clinical trial. JAMA Ophthalmol. Published online April 23, 2026. doi: 10.1001/jamaophthalmol.2026.1008

2. 2.Bressler NM, Beck RW, Ferris FL III. Panretinal photocoagulation for proliferative diabetic retinopathy. N Engl J Med. 2011;365:1520-6. doi:10.1056/NEJMct0908432

3. 3.Reddy SV, Husain D. Panretinal photocoagulation: a review of complications. Semin Ophthalmol. 2018;33:83-8. doi:10.1080/08820538.2017.1353820

4. 4.Shimura M, Yasuda K, Nakazawa T, Tamai M. Visual dysfunction after panretinal photocoagulation in patients with severe diabetic retinopathy and good vision. Am J Ophthalmol. 2005;140:8-15. doi:10.1016/j.ajo.2005.02.029

5. Nguyen QD, Das A, Do DV, et al. Brolucizumab: evolution through preclinical and clinical studies and the implications for the management of neovascular age-related macular degeneration. Ophthalmology. 2020;127:963-76. doi:10.1016/j.ophtha.2019.12.03